title: Regulation of mitochondrial processes by protein S-nitrosylation.
abstract: BACKGROUND
  Nitric oxide (NO) exerts powerful physiological effects through guanylate cyclase (GC), a non-mitochondrial enzyme, and through the generation of protein cysteinyl-NO (SNO) adducts-a post-translational modification relevant to mitochondrial biology. A small number of SNO proteins, generated by various mechanisms, are characteristically found in mammalian mitochondria and influence the regulation of oxidative phosphorylation and other aspects of mitochondrial function.
  
  
  METHODS
  The principles by which mitochondrial SNO proteins are formed and their actions, independently or collectively with NO binding to heme, iron-sulfur centers, or to glutathione (GSH) are reviewed on a molecular background of SNO-based signal transduction.
  
  
  CONCLUSIONS
  Mitochondrial SNO-proteins have been demonstrated to inhibit Complex I of the electron transport chain, to modulate mitochondrial reactive oxygen species (ROS) production, influence calcium-dependent opening of the mitochondrial permeability transition pore (MPTP), promote selective importation of mitochondrial protein, and stimulate mitochondrial fission. The ease of reversibility and the affirmation of regulated S-nitros(yl)ating and denitros(yl)ating enzymatic reactions support hypotheses that SNO regulates the mitochondrion through redox mechanisms. SNO modification of mitochondrial proteins, whether homeostatic or adaptive (physiological), or pathogenic, is an area of active investigation.
  
  
  CONCLUSIONS
  Mitochondrial SNO proteins are associated with mainly protective, bur some pathological effects; the former mainly in inflammatory and ischemia/reperfusion syndromes and the latter in neurodegenerative diseases. Experimentally, mitochondrial SNO delivery is also emerging as a potential new area of therapeutics. This article is part of a Special Issue entitled: Regulation of cellular processes by S-nitrosylation.
authors.affiliation: Departments of Medicine and Pathology, Box 3315, Duke University Medical Center, Durham, NC 27710, USA. Piant001@mc.duke.edu
authors.forename: Claude A
authors.initials: CA
authors.lastname: Piantadosi
mesh_terms: D000818:Animals; D003545:Cysteine / Q000737:chemistry / Q000378:metabolism; D005978:Glutathione / Q000737:chemistry / Q000378:metabolism; D006162:Guanylate Cyclase; D006801:Humans; D008928:Mitochondria / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D015538:Nitrosation; D010084:Oxidation-Reduction; D010085:Oxidative Phosphorylation; D017382:Reactive Oxygen Species / Q000378:metabolism; D026403:S-Nitrosothiols / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D024101:Mitochondrial Proteins; D017382:Reactive Oxygen Species; D026403:S-Nitrosothiols; D009569:Nitric Oxide; D006162:Guanylate Cyclase; D005978:Glutathione; D003545:Cysteine